Masashige is a main character of Ginga Densetsu Weed: Orion.
He is a member of the Kurohabaki Clan and the vassal of the leader Masamune Kurohabaki. But after failing his mission two times Masamune betrays him and kicked him out of his pack. Since that Masashige lives a life as a loner, full of regrets because of his past misdeeds.
Masashige is a medium-large sized Akita-mix. He has solid white fur, with a few dark spots on his muzzle. His eyes are glossy and completely yellow.
Masashige is known for following the most evil orders without any complaint, thus he doesn't really have any compassion. He mentioned himself that he'd even kill women and children without any complaint if Masamune ordered him to. He is also quite serious.
After meeting Unsai, he changes himself, trying to become a better individual.
As Kurohabaki's vassal
Later, Masashige was given the task to eliminate all the inhabitants who lived in the Kurohabaki clan's territory and he sets out in the storm with his platoon of 4 dogs to find them. Masashige's platoon killed the old Mutsu general Kisaragi and Izō's wife, Sayako, and three of her puppies. Masashige didn't like murdering, but viewed it as an unfortunate task that must be done.
After the massacre, they return to their pack, not knowing that Kisaragi's sons are still alive. Later, Izō and his brothers attack the Kurohabaki clan's base to avenge their family. As Masashige and his troops went down the fortress to investigate the situation, he notices Izō's resemblance to his father and son, which he killed, and Izō and his brother immediately attack him. Luckily, reinforcements came and Masashige had the advantage of winning. Masashige almost kills Izō, but Orion saves his friend. Izō, his brothers and Orion's friends try to escape, but Masamune orders Masashige and his platoon to pursue the Ōu soldiers and to kill them. He and his platoon manages to catch up to them in a gorge and fights Miu, Izō's brother and the battle began once more. Although it seemed as if Masashige and his clan would win, the Ōu soldiers howl in the air, causing an avalanche. Despite the loss of many Kurohabaki clan members, Masashige survives the incident and this time, he swears to catch the red Akita and to kill him.
When Masashige and his new army continue to follow the Ōu soldiers, they bump into Tesshin and his pack, who wouldn't allow them to take a step farther into his territory. As Masashige and his army charges toward them, Tesshin and his followers use the Battōga on them, and he manages to rip off his left ear. Saburō, Izō's brother, also attacks him and uses the spin attack on Masashige's throat, nearly killing him. As the husky would give him the finishing blow, Masashige grabs his neck, but is forced to release when Tesshin attacks him as well. The Kurohabaki clan eventually surrendered because their leader was caught by the enemy. Masashige is then kept as a hostage by the Ōu soldiers in attempt to make Masamune come to their territory so they can assassinate him.
After Tesshin's followers left by their leader's orders, Tesshin drops Masashige near a tree, so he can be close enough to use the Battōga on Masamune. When the Kurohabaki clan arrives, Masamune notices Masashige half dead and therefore banish him from the clan for failing his mission and Masashige cries in regret.
Masashige's condition was not heard about much after his defeat by Tesshin, until it was revealed in the later chapters that he was still alive. The wounded Masashige wandered helplessly and disillusioned looking for a place to die when he came across the Sanada Clan. He spends some time with them and was enlightened with their ways. He thanks the leader, Sanada Nyūdōunsai, and continues travelling.
He later encounters Kurokirimaru and his brother's pack of young dogs, along with Rigel and Kotetsu. Though he was banished from the clan, Masashige manages to trick Kurokirimaru and his brothers by telling them that he was sent by Masamune, to inform them that they are to be needed for his campaign on invading Shikoku. Kurokirimaru, Tsumuji and Kōsetsu are easily fooled by his words, and they leave, making Masashige the new head of the small pack of youngsters. When he reveals to Rigel that he killed the old Ōu soldier Kisaragi, Rigel is enraged and uses the Ningatō attack on Masashige, but inflicts a minor blow to his throat. Impressed by this attack, Masashige tells Rigel and Kotetsu that he fully regretted to have killed Kisaragi, and that he does not belong to the Kurohabaki clan anymore.
Masashige decides to travel with Rigel and Kotetsu for a while until they are under attack by one of the trio of kai-kens of Kurohabaki clan: Shikkoku, Gekka and Kurogane. Masashige charges into them and easily kills two of them, except Shikkoku who managed to escape. Masashige then orders Rigel and Kotetsu to continue their journey without him, and that he wishes them good luck. When Masashige finally catches Shikkoku, he is surrounded by Kurokirimaru and his brothers. Masashige puts up a good fight but is outnumbered by the others, and is then badly beaten by them. However, although he is bleeding badly, he refuses to give up, and keeps on fighting. He is pinned to the ground by Kōsetsu who rips open his stomach. Masashige manages to lock Kōsetsu neck at a 90 degree angle, paralyzing him before dying of blood loss. Before he died, Unsai appears in a vision and he remembered his enlightening words of wisdom. Masashige then howls a bloody roar and cries, wishing he will be reborn among Ōu's soldiers. He then fell dead of blood loss. After Kurokirimaru and his pack left, Masashige's body is buried by Rigel and Kotetsu shortly afterward.